1. Technical Field
Example embodiments relate generally to semiconductor integrated circuits, and more particularly to nonvolatile memory devices and/or methods of operating nonvolatile memory devices.
2. Discussion of Related Art
Semiconductor memory devices may be classified as volatile semiconductor memory devices and nonvolatile semiconductor memory devices. Volatile semiconductor memory devices may perform read and write operations at high speed. Contents stored in volatile memory devices may be lost when the devices are powered-off. Nonvolatile semiconductor memory devices may retain contents stored therein even when powered-off. For this reason, nonvolatile semiconductor memory devices may be used to store contents to be retained regardless of whether the devices are powered on or off.
Nonvolatile semiconductor memory devices may include a mask read-only memory (MROM), a programmable ROM (PROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), etc.
A flash memory device is an example of a nonvolatile memory device. A flash memory device may be widely used as the voice and image storing media of electronic apparatuses such as a computer, a cellular phone, a PDA, a digital camera, a camcorder, a voice recorder, an MP3 player, a handheld PC, a game machine, a facsimile, a scanner, a printer, etc.
As high integration memory devices have recently become increasingly used, multi-bit memory devices storing multi-bit data in a memory cell have become more common.